- N-NITROSAMINES AS REAGENTS FOR THE =C=S=C=O TRANSFORMATION
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N-nitrosopiperidine and N-nitroso-N-methylaniline react in acidic solution with thiocarbonyl compounds to give the corresponding carbonyl analogues.Secondary- and tertiary thioamides, xanthione, thio- and dithiobutyrolactone, thiocoumarin, certain thiourea derivatives, dithio-O,O-thiocarbonic, S,S-trithiocarbonic- and N,N disubstituted thiocarbamic esters are all converted into the corresponding O-analogues.Thiobenzamide and N-phenylthiourea yield 1,2,4-thiadiazoles.All the reactions are run with iodide (I-) as NO+-carrier.The kinetics of the reaction have been studied under pseudo-first order conditions, and the reaction rate is proportional to the Pearson's nucleophilicity parameter of ions.The =C=S =C=O transformation is also found to take place in gastric juice.
- Jorgensen, K. A.,El-Wassimy, M. T. M.,Lawesson, S. -O.
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- AN EXCEPTIONALLY MILD, PHASE TRANSFER CATALYZED METHOD FOR THE CONVERSION OF THIOCARBONYL COMPOUNDS TO CARBONYLS
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The thiocarbonyl group of thioketones, dithioesters, thioamides, and thioureas can be converted to the carbonyl function by treatment with sodium hydroxide under phase transfer conditions.
- Alper, Howard,Kwiatkowska, Caroline,Petrignani, Jean-Francois,Sibtain, Fazle
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- Theoretical Study, Synthesis, and Reactivity of Five-Membered-Ring Acyl Sulfonium Cations
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The feasibility of the cyclization of γ-alkylthiobutyric acid derivatives to form previously unknown five-membered-ring acyl sulfonium cations was studied. Experimental results were in good agreement with our DFT calculations that predicted such cyclizations to be easy if starting with acyl iodides and mixed anhydrides of triflic acid. Particularly efficient were the reactions of γ-alkylthiobutyryl fluorides with trimethylsilyl triflate in CDCl3 solution, which led to cyclic acyl sulfonium triflates. In some cases, the observed acyl sulfonium salts were stable enough to be characterized by NMR spectroscopy. They were found to be both alkyl-transfer reagents and acylating agents. They react with amines to form amides. These findings lend some weight to our hypothesis that the acyl sulfonium derived from methionine may have played a major role in the prebiotic synthesis of the first peptides on the primitive Earth. The reaction of trimethylsilyl triflate (Me3SiOTf) with γ-alkylthiobutyryl fluorides leads to previously unknown acyl sulfonium cations. These reactive species react both as alkyl-transfer reagents (e.g., with sulfides) and as acylating reagents (e.g., with amines). Such reactivity suggests that the acyl sulfonium derived from methionine may have been able to do the same in the primitive ocean.
- Rao, K.V. Raghavendra,Caiveau, Nicolas,David, Rolf,Shalayel, Ibrahim,Milet, Anne,Vallée, Yannick
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- Efficient Synthesis of γ-Lactones by Cobalt-Catalyzed Carbonylative Ring Expansion of Oxetanes under Syngas Atmosphere
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A practical route from oxetane or thietane to γ-(thio)butyrolactone via solvated-proton-assisted cobalt-catalyzed carbonylative ring expansion under syngas atmosphere has been established. A wide variety of γ-(thio)butyrolactones can be afforded in good to excellent yields. The versatility of this method has been well demonstrated in the synthesis of intermediates towards the natural product Arctigenin as well as the pharmaceuticals Baclofen and Montelukast. The observed promoting effect of glycol ether solvent has been rationally interpreted.
- Tang, Yitian,Shen, Chaoren,Yao, Qiyi,Tian, Xinxin,Wang, Bo,Dong, Kaiwu
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- Synthesis of thiolactones using benzyltriethylammonium tetrathiomolybdate as sulfur transfer reagent
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An interesting sulfur transfer reaction mediated by benzyltiethylammonium tetrathiomolybdate [(PhCH2NEt3)2MoS4] converts ω-halo acid chlorides to the corresponding thiolactones in moderate to good yields in one
- Bhar, Debjani,Chandrasekaran
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- Regiospecific Carbonylation and Ring Expansion of Thietanes and Oxetanes Catalyzed by Cobalt and/or Ruthenium Carbonyls
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Dicobalt octacarbonyl and triruthenium dodecacarbonyl together catalyze the regiospecific insertion of carbon monoxide into the least substituted carbon-heteroatom bond of a thietane or oxetane, affording thiobutyrolactones or butyrolactones in fine yields.
- Wang, Ming-De,Calet, Serge,Alper, Howard
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- Indium-catalyzed direct conversion of lactones into thiolactones using a disilathiane as a sulfur source
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An indium-catalyzed reaction of lactones and a disilathiane leading to thiolactones is described. The direct synthesis of thiolactones from lactones with an appropriate sulfur source is one of the most attractive approaches in organic and pharmaceutical chemistry. In this context, we found an indium-catalyzed direct conversion of lactones into thiolactones in the presence of elemental sulfur and a hydrosilane via formation of the disilathiane in situ. On the basis of the previous reaction, the application utilizing the disilathiane as a sulfur source was performed herein for the efficient synthesis of a variety of thiolactone derivatives from lactones by an indium catalyst.
- Ogiwara, Yohei,Takano, Ken,Horikawa, Shuhei,Sakai, Norio
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- COMPOUNDS FOR A CONTROLLED RELEASE OF ACTIVE PERFUMING MOLECULES
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The present invention relates to the field of perfumery. More particularly, it concerns compounds comprising at least one β-thio carbonyl or nitrile moiety capable of liberating an active molecule selected from an α,β-unsaturated ketone, aldehyde or nitrile. The present invention concerns also the use of said compounds in perfumery as well as the perfuming compositions or perfumed articles comprising the invention's compounds. (I) wherein: a) m represents an integer from 1 to 6; b) Pro represents a hydrogen atom or a group susceptible of generating an odoriferous α,β-unsaturated ketone, aldehyde or nitrile and is represented by the formulae (II) or (II') in which the wavy line indicates the location of the bond between said Pro and the sulfur atom S; and at least one of the Pro groups is of the formula (II) or (II').
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Page/Page column 39-40
(2013/10/08)
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- Catalytic synthesis of thiobutyrolactones via CO insertion into the C-S bond of thietanes in the presence of a heterodinuclear organoplatinum-cobalt complex
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Heterodinuclear organoplatinum-cobalt complex having a 1,2-bis(diphenylphosphino)ethane ligand (dppe)MePt-Co(CO)4 catalyzes CO insertion into the C-S bond of thietanes in THF at 100°C under 1.0 MPa of CO for 2 h to give γ-thiobutyrolactone in q
- Furuya, Masaki,Tsutsuminai, Susumu,Nagasawa, Hiroto,Komine, Nobuyuki,Hirano, Masafumi,Komiya, Sanshiro
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p. 2046 - 2047
(2007/10/03)
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- Nickel-mediated formation of thioesters from bound methyl, thiols, and carbon monoxide: A possible reaction pathway of acetyl-coenzyme A synthase activity in nickel-containing carbon monoxide dehydrogenases
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Current mechanistic proposals for the acetyl synthase activity of nickel-containing carbon monoxide dehydrogenases (CH3-THF + CoA·SH → CoA·SCOCH3 + THF; THF = tetrahydrofolate, CoA·SH = coenzyme A) implicate a Ni catalytic center and the steps [Ni-CH3] → [Ni-COCH3] → CoA·SCOCH3. The second step presumably involves attack by the sulfur nucleophile of coenzyme A at the acyl carbon atom in the overall reaction [NiII-COCH3] + RS(H) → RSCOCH3 + NiII (+ H+) + 2e-. We have previously demonstrated these steps in Ni(II) complexes with physiological-type ligation. In this work, it is shown that the reaction of acyl and thiolate ligands coordinated to Ni(II) affords thioesters in high yield. The complex [Ni(bpy)(CH3)2], established to be planar by an X-ray structure determination, reacts with 1 equiv of arenethiol to afford diamagnetic planar [Ni(bpy)(CH3)(SR)] (8) with R = p-C6H4CH3, 2,6-C6H3(CH3)2 (8b), mesityl (8c), 2,4,6-C6H2iPr3, and 2,6-C6H3Cl2 (8e) (bpy = 2,2′-bipyridyl). An analogous reaction gives [Ni(bpy)(C2H5)(S-mesityl)] (12) from [Ni(bpy)(C2H5)2]. Planar structures of 8c,e were confirmed by X-ray analysis. Complexes 12 and 8 with different R substituents undergo thiolate ligand exchange in THF with Keq ≈ 1. Reaction of 8e with 1 equiv of carbon monoxide yields the acyl complex [Ni(bpy)(COCH3)(S-2,6-C6H3Cl2)] (9a), whose planar coordination unit was confirmed by X-ray methods. Treatment of the complexes 8 in THF with more than 3 equiv of carbon monoxide yields [Ni(bpy)(CO)2] and the thioesters RSCOCH3 in 96-100% yield in situ. A solution initially containing 8b and 12 gave under the same conditions four thioesters in equal amounts, consistent with four complexes in the equilibrated solution prior to reaction with carbon monoxide. Reaction of 9a in THF with carbon monoxide produced 2,6-dichlorophenyl thioacetate quantitatively, indicating that Ni(II)-acyl-thiolate complexes are intermediates in thioester formation. The overall reaction is [Ni(bpy)(R′)(SR)] + 3CO → RSCOR′ + [Ni(bpy)(CO)2] (R′ = CH3, C2H5); the two electrons in the generalized reaction are captured by the metal as Ni(0). A related and necessarily intramolecular reaction of [Ni(bpy)(SCH2-CH2CH2)] was confirmed and shown to produce γ-thiobutyrolactone in quantitative yield in situ. Evidence supporting an analogous intramolecular path for reaction systems based on 8 is summarized. This investigation provides the first examples of Ni-mediated acyclic thioester synthesis and demonstrates a possible means of enzymatic thioester formation should coenzyme A- and an acetyl group coordinate to the Ni(II) catalytic center.
- Tucci, Gregory C.,Holm
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p. 6489 - 6496
(2007/10/02)
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- Studies on organophosphorus compounds. XLV. Thiation of some sterically hindered N-nitrosamides
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Some sterically hindered N-nitrosamides have been prepared using sodium nitrite in aqueous acid solution.Reaction of these N-nitrosamides with 2,4-bis-(4-methoxyphenyl)-1,2,3,4-dithiadiphosphetane-2,4-disulfide (Lawesson's Reagent ) causes thiation of both the carbonyl and the nitroso groups followed by destruction of the nitroso group giving ultimately the corresponding thioamides and amides as the main products.Dihydro-2(3H)-thiophenone is isolated as a by-product when N-nitroso-dihydro-2(3H)-pyrrolidinone is reacted with LR.A mechanism for its formation is postulated.Thiation of the sterically hindered amides yields the thioamide as rotamers which in two cases could be separated by column chromatography.Ames test has been performed for some of the compounds.
- Joergensen, Karl Anker,Ghattas, Abdul-Badik,Lawesson, Sven-Olov
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p. 204 - 208
(2007/10/02)
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- ANODIC OXIDATION OF COMPOUNDS HAVING BENZYLIC OR ALLYLIC CARBON AND α-CARBON TO HETERO ATOM USING N-HYDROXYPHTHALIMIDE AS A MEDIATOR
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Benzylic, allylic carbons and the carbon α to hetero atoms are electrochemically oxidized to the corresponding carbonyl group in the presence of N-hydroxyphthalimide under mild conditions.KEYWORDS - anodic oxidation; mediator; N-hydroxyphthalimide; benzylic carbon; allylic carbon; ether; sulfide; amide
- Masui, Masaichiro,Hara, Seijiro,Ueshima, Takahiro,Kawaguchi, Tetsuo,Ozaki, Shigeko
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p. 4209 - 4212
(2007/10/02)
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